The usual way to improve your life expectancy is through a healthy lifestyle of some-sort, especially during peace time.
However, in many plausible futures, personal health now seems to have little effect:
- We create aligned AGI: aligned AGI could presumably solve any health problems we accumulated due to our lifestyle choices.
- We create unaligned AGI: unaligned AGI would definitely solve any health problems we accumulated due to our lifestyle choices.
- Humans solve aging without AGI: health problems we accumulated probably don't matter in this scenario.
- Some other existential crisis occurs.
Whereas the scenarios where health choices do effect longevity seem slim:
- Humans do not invent AGI and to do not solve aging themselves and no existential catastrophes occur in your lifetime
- No existential catastrophes occur, we/an AI do find a cure for aging, but medical regulations prevent the cure from being distributed widely (please no 🙏).
One important consideration to keep in mind though is that things that extend our life expectancy usually have short term health benefits as well. For example, sleep, diet, and exercise have a massive effect on energy levels. But if you're only optimizing short-term health, does the optimal lifestyle look different?
I very much believe aligned AGI isn't going to just solve our problems overnight. It would have to be on the absolute far end of capability for that, IMO. Less-than-arbitrarily-powerful AGI is going to take time (years to decades) to figure out enough about biology to upload/fix our organic hardware while keeping us intact. Even for me, with my rather lax requirements about continuity (not required) and lax requirements of hardware platform (any), I expect it to take years if not decades.
Humans, barring extinction, will eventually solve aging. My best guess at the moment is that we'll hit longevity escape velocity around 2050; this is really inconvenient for me, because I am already old. My odds of dying due to organic hardware platform failure are IMO higher than my odds of dying from AGI ruin in that time.
So from my standpoint, investing in platform maintenance (a healthy lifestyle) makes sense. Platform failure is a substantial chunk of my probability space, and I'm old enough that there are qualify of life benefits to be had as well.
If you're only 20, AGI ruin will probably be a larger part of your probability space than platform failure. YMMV.